1. Field of the Invention
The present invention relates to an IC card which is fed electricity by an IC card reader-writer via electromagnetic or electrostatic coupling (that is, power is supplied from the IC card reader-writer to the IC card), and between these IC card and IC card reader-writer, data transmission is performed. In particular, the present invention relates to an IC card having a function of indicating its state of usage and a system therefor, and a method for indicating a state of usage.
This application is based on Patent Applications No. Hei 9-247713 filed in Japan, the contents of which are incorporated herein by reference.
2. Description of the Related Art
In conventional prepaid cards such as phone cards, figures and punch holes are provided for indicating whether the card has already been used, or how much the card has been used. In more detail, on a back face (or the like) of the card, figures indicating charges and corresponding degrees of use are previously indicated from a lower limit to an upper limit, and by punching a hole near each figure, the present state of usage is shown to a user.
Regarding conventional contact and contactless IC cards, no means for indicating a state of usage is provided in the card itself, but only in a display area of an external device which includes an IC card reader-writer, a state of usage of the IC card is displayed.
FIG. 11 is a perspective view showing electromagnetic coupling type contactless IC card C100.
The IC card C100 comprises card substrate 100B, coil 100C for electromagnetic coupling, IC chip 100CH, and outside terminals (or pads) 100T1 and 100T2 for the IC chip. A PVC (polyvinyl chloride) resin, an ABS resin, or a PET (polyethylene terephthalate) resin may be used for making card substrate 100B. The IC chip 100CH and electromagnetic coupling coil 100C, which are connected to each other via outside terminals 100T1 and 100T2, are arranged inside the card substrate 100B or are put between two portions of the substrate. The contactless IC card C100 is electromagnetically coupled with IC card reader-writer 200 having electromagnetic coupling coil 200C, and thereby the IC card and the reader-writer are wirelessly communicated with each other.
The IC card reader-writer 200 comprises the electromagnetic coupling coil 200C which is electromagnetically coupled with coil 100C of IC card C100.
The thickness of conventional contact and contactless IC cards is larger than that of magnetic cards; thus, it is difficult to punch a hole and indicate a state of usage as in the case of a magnetic prepaid card. In addition, if a function of punching a hole is provided in public telephones, construction of the public telephone becomes complicated and thus trouble may be caused.
When the contactless IC card C100 wirelessly communicates with an external device including IC card reader-writer 200, the contactless IC card C100 is not attached to the above external device; thus, it is impossible to record, in a specified or predetermined area on a surface of the card, a state of usage of the card by, for example, punching a hole, as in the case of a magnetic prepaid card.
Therefore, even if the user of an IC card desires to know a state of usage of this IC card, that is, whether the card has already been used or how much the card has been used, the user cannot obtain information about the state of usage from the appearance of the card and thus it is inconvenient. Additionally, in the conventional situation, there occurs a problem in which fraudulent practices such as selling a used IC card on the pretence that it is a new card are possible.
In order to solve the above problems, an object of the present invention is to provide an IC card whose state of usage can be judged by a user from an appearance of the card, a relevant IC card system, and a method for indicating a state of usage of an IC card.
In order to realize the above object, the present invention provides an IC card fed electricity from an IC card reader-writer via feeding means using one of electromagnetic coupling and electrostatic coupling, and the IC card having an IC chip which communicates with the IC card reader-writer, wherein the possible/impossible state of usage of the card by a user is determined using electric means for disconnecting or non-disconnecting the feeding means or providing another circuit and disconnecting this circuit, and the appearance of the IC card is also changed at the time of the change caused by such electric means and thereby the state of usage of the card is indicated to the user.
The following are possible IC cards comprising an electric means:
(1) the IC card comprises a conductor for short-circuiting the feeding means, and becomes usable when the short-circuited state of the conductor is freed.
(2) the IC chip comprises two lead wire connecting terminals, and the IC card comprises a conductor for short-circuiting the two lead wire connecting terminals and becomes usable when the short-circuited state of the connecting terminals is freed.
(3) the IC card comprises means for generating a current having a reversed polarity with respect to a current generated by the feeding means, and becomes usable when the current of the reversed polarity is disconnected.
In order to make the card usable, it is possible to cut and separate a portion of the card. In cases (1) and (2) above, the IC card may have a notch and a portion of the conductor is exposed at the notch, and the short-circuited state may be freed by cutting the exposed conductor. In case (3) above, the IC card may have a notch and a portion of the means for generating the current having the reversed polarity is exposed at the notch, and the current of the reversed polarity may be disconnected by cutting the exposed portion of said means.
In case (2) above, it is also possible that before the IC card becomes usable, the IC card performs specified data communication prior to usage of the card, with the IC card reader-writer.
Generally, the IC card may comprise indicating means for indicating information relating to a state of usage of the IC card. Such indicating means can be easily realized using a fuse or a thermochromic material. In addition, a plurality of the fuses or thermochromic materials may be provided, and thereby it is possible to indicate whether the card reaches each of predetermined degrees of use.
The present invention also provides an IC card system comprising an IC card which has any of the above-described features and an IC card reader-writer. The present invention further provides a method of indicating a state of usage of an IC card having a corresponding feature.
According to the present invention, the user who obtains the IC card can easily and surely confirm that the IC card has not yet been used before the user suitably starts to use the card. It is also possible for the user to obtain information relating to a state of usage of the card in use.